Illuminated wall switch plate



March 12, 1940. J. M. REED 2,193,740

ILLUHINATED WALL SWITCH PLATE Filed Sept. e, 1938 15' V 1 :LE.

I ;EI.3- 1 I 1 22 7 23 25 25 INVENTOR 25 John. Q$Qd Patented Mar. 12,1940 UNITED STATES PATENT OFFICE 4 Claims.

My invention relates to cover plates for electrical wall switches andmore particularly to a cover plate supporting a gaseous pilot lightbulb, which is permanently connected to the switch terminals and whichglows and indicates in the dark the position of the switch.

Switch plate covers of this type have the advantage that although the'main circuit through the switchis interrupted, the switch plate may beconstantly illuminated by the pilot bulb without using any appreciableamount of current.

Heretofore, the installation of switch plate covers of this type,required that a connection be made with the switch terminals, which wasaclB 'complished by unscrewing the latter, inserting the ends of theflexible wires leading to the pilot bulb electrodes, and then againtightening the terminal screws. The installation involved considerabledanger and further required time and skill because to attach the leadwires of the plate without short-circuiting and receiving an electricshock, it was necessary to temporarily disconnect the entire switch fromthe main circuit by removing a fuse; In view of the danger anddifficulties associated with the mounting of the illuminated switchcover plate, the commercial value of the device was greatly reduced.

It is one object of my invention to provide a cover plate with a gaseouspilot light bulb which automatically makes its electrical contacts withthe switch terminals as the plate is being attached to the wall switchcasing.

Another object of my invention is to produce a cover plate of the typewhich connects the bulb to the switch terminals without disconnectingthe switch from the circuit, and while the circuit through the switch isclosed.

A still further object of my invention is to devise a model switch boxwhich in combination with my novel cover plate maybe used to demonstrateto buyers the extremely simple and entirely unharmful method used toattach the new cover plate to a wall switch.

I accomplish these and other objects, which will appear as thespecification proceeds, by means of the new structure, arrangement andcombination of elements described in the following description and setforth in the appended-claims. My invention is illustratively exemplifiedin the accompanying drawing in which:

Fig. 1 is a, front elevational view of my novel switch plate mounted onamodel switch box according to the invention.

5 Fig. 2 is a substantially longitudinal sectional on the studs 4 bymeans of screws ll.

view taken. on line II-II of Fig. 1 showing certain parts in elevation.

Fig. 3 is a partial elevational view of the dismounted cover plate seenfrom the inside.

Fig. 4 is a perspective view of the yieldable 5 contact piece andassociated parts; and

Fig. 5 is a sectional view of a modified embodiment of the contactpiece.

Referring to the drawing, l denotes a rectangular box. preferably ofBakelite or the like 10 material, open at its back and provided with acircular opening 2 in its top wall and a rectangular cut-out 3 in itsfront wall. Integral with the front wall of the box I and inwardlyprojecting therefrom are four conical studs 4. A ll usual snap switchelement comprising switch casing 5, porcelain core 6 provided withswitch mechanism (not shown), switch operating lever 8, front bracket 9,and terminals I0, is mounted An in- 20 sulated double lead wire i2 isintroduced into the open back of the box I, leads into the switch casing5, and then to the socket l3 of an electric bulb I! which is disposed onthe top of the box I and projects downwardly through the opening 2 intothe socket l3. The wire I2 is separated into two strands l4 and I4 at apoint in the casing 5, one of said strands, I, passing uninterruptedthrough the casing while the other strand i4 is severed and the two free30 ends are connected to the two terminals 10 of the switch. Thus, whenthe cord I2 is connected to a. supply main, operation of the lever 8opens and closes the circuit including the bulb i3.

A cover plate I5 is secured to the switch by 35 7 means of screws I6engaging threaded holes in the front bracket 9. The plate I5 is providedwith a substantially central opening I! to accommodate the switch lever8. An outwardly projecting and rearwardly open pilot light hous- 0 ingi8 is disposed on and adjacent the upperedge of the plate ii, thehousing i8 being integral with the latter and provided with a pilotopening I! in its front wall and a light pervious window 20 covering theopening on the inside thereof. A gaseous pilot light bulb M is containedin a carrier box 22, which is supported in the housing I8. The carrierbox 22 is open at the front and flts tightly into'the housing It. Theelectrodes of the bulb 2i terminate in lead 50 wires 23, connecting saidterminals to two yieldable contact pieces 24, respectively, whichcontact pieces project inwardly from the inner wall of the plate l5 andare secured thereto in register with the terminals Not the switch.

According to Figs. 1 to 4 each yieldable contact piece comprises a baseplate 24 screwed to the plate l5 and a spiral spring 25 mounted on saidbase plate and projecting inwardly a distance exceeding that existingbetween the base plate 24 and the corresponding terminal l when theplate I is mounted on the switch. Thus, upon securing the cover plate l5to the switch the inner free ends of springs 25 contact and are pressedagainst the terminals l0, respectively, and insure automatically aneffective and permanent electrical connection.

Fig. 5 illustrates a further embodiment of a contact piece according tothe invention in which the spring 25 is guided in a stationarycylindrical sleeve 21 integral with the base plate 24 and urges aprojecting pin 28 of conducting material disposed slidably in saidsleeve towards th switch terminal "I.

I claim:

1. A cover plate for a switch provided with terminals to receive thewires of an electric circuit, said plate supporting a gaseous light bulbvisible from the outside of said plate, yieldable contact elementsprojecting inwardly from the inner wall of said plate to contact theswitch terminals, and means permanently and electrically connecting theelectrodes of said bulb to said contact elements.

'2. A cover plate, as claimed in claim 1, in which each of saidyieldable contacts comprises a base plate fastened to said cover plate,and a spiral spring-mounted on said base plate and projecting inwardlytherefrom a distance exceeding that existing between the base plate andthe corresponding switch terminal when the cover plate is mounted on theswitch.

3. A cover plate, as claimed in claim 1, in which each of said yieldablecontacts comprises a base plate fastened to said cover plate, acylindrical guide sleeve integral with said base plate and projectinginwardly therefrom, a contact pin disposed slidably in said sleeve andadapted to project inwardly therefrom, and a pressure spring in saidsleeve between said pin and said base plate.

4. In combination, a substantially rectangular box having a rectangularopening in one of its walls, an electric light bulb disposed on theoutside of said box, a switch mounted in said box rearwardly of saidopening and having a switch operating member projecting through thelatter, and connecting terminals in its forward portion, electricconductors connected to said terminals and said bulb and adapted toconnect the latter in series with said switch into a supply circuit anda cover plate secured to said box and switch, said cover platesupporting a gaseous light bulb visible from the outside of said plate,yieldable contact elements projecting inwardly from the inner wall ofsaid plate to contact the switch terminals and means permanently andelectrically connecting the electrodes of said gaseous bulb to saidcontact elements.

J OHN M. REED.

